Avoid UTF-8 decoding in num.toString.

Avoid UTF-8 decoding in num.toString.

4-7% speedup on SplayHarder.

Introduce _Num class to make Dart and VM hierarchies match and enable sharing code between integers and doubles.

R=iposva@google.com

Committed: https://code.google.com/p/dart/source/detail?r=39383

[koda, 2014-08-19 19:39:57]

Uploaded new version with _Num class. Running on go/darta now to ensure it's not
slower. PTAL

[Ivan Posva, 2014-08-19 20:37:18]

LGTM with the class hierarchy issues addressed.

-Ivan

https://codereview.chromium.org/473673004/diff/80001/runtime/lib/num.cc
File runtime/lib/num.cc (right):

https://codereview.chromium.org/473673004/diff/80001/runtime/lib/num.cc#newco...
runtime/lib/num.cc:12: DEFINE_NATIVE_ENTRY(num_toString, 1) {
Num_toString or Number_toString, depending on the eventual name of the class.

https://codereview.chromium.org/473673004/diff/80001/runtime/lib/num.dart
File runtime/lib/num.dart (right):

https://codereview.chromium.org/473673004/diff/80001/runtime/lib/num.dart#new...
runtime/lib/num.dart:5: class _Num extends num {
We should not extend num, if anything at all this should implement num. In any
case this should really be an abstract class. You can also roll the code from
the patch into here, as this is not a SDK class and is internal to the VM.

[koda, 2014-08-19 21:15:18]

https://codereview.chromium.org/473673004/diff/80001/runtime/lib/num.cc
File runtime/lib/num.cc (right):

https://codereview.chromium.org/473673004/diff/80001/runtime/lib/num.cc#newco...
runtime/lib/num.cc:12: DEFINE_NATIVE_ENTRY(num_toString, 1) {
On 2014/08/19 20:37:18, Ivan Posva wrote:
> Num_toString or Number_toString, depending on the eventual name of the class.

Done.

https://codereview.chromium.org/473673004/diff/80001/runtime/lib/num.dart
File runtime/lib/num.dart (right):

https://codereview.chromium.org/473673004/diff/80001/runtime/lib/num.dart#new...
runtime/lib/num.dart:5: class _Num extends num {
On 2014/08/19 20:37:18, Ivan Posva wrote:
> We should not extend num, if anything at all this should implement num. In any
> case this should really be an abstract class. You can also roll the code from
> the patch into here, as this is not a SDK class and is internal to the VM.

Done.

[koda, 2014-08-19 21:15:46]

Committed patchset #7 manually as r39383 (presubmit successful).